The present invention relates to a composite band for lids for thermoplastic containers having a flat and preferably horizontal upper edge or rim, said composite band being of the type comprising downward from the top: a first thin band in aluminum or equivalent material, a thermo-adhesive film bonded to the lower face of the first band, and a second band in thermoplastic material adhering to the first band via said thermo-adhesive film and adapted to be separated therefrom by peeling off, said second band having, in each part corresponding to the position of each lid to be subsequently cut out, at least one slit of curved configuration defining a passage and the ends of which are either located closely or coinciding.